Warts are one of the most common skin conditions, frequently encountered in childhood. They are small, harmless skin growths that may spread, but are not cancerous.
What causes warts?
Warts are caused by human papilloma viruses, of which there are 60-70 different types. The virus invades the skin, and stimulates the skin cells to rapidly multiply. The virus may lie inactive in the skin for several months before it triggers the growth.
What are the symptoms?
Warts start as a pinhead sized, flesh coloured lumps which grow over several weeks to form a firm, rough nodule 1-10mm in size. They may contain black spots of pigment. Warts may be isolated, or they may occur in crops. Warts can be divided into several different types depending on their appearance:
- Common warts – Firm growths on the skin with a rough surface. They may be round or irregular in shape and are typically grey, brown, or skin coloured. Common warts most often occur at sites that are frequently injured such as the hands, elbows and knees. They may occur around the nail in response the biting or picking.
- Plane warts – These growths are firm and flat-topped. They most often occur on the face and legs. The warts may be spread through minor skin trauma (like scratching or shaving), and may join together to form larger plaques.
- Plantar warts – These warts occur on the weight bearing parts of the sole of the foot. They appear as a round lump with a collar of thickened skin, and may have visible spots of bleeding. Plantar warts are often painful when pressure is applied.
- Filiform warts – These are long, thin, finger-like warts that commonly occur on the face around the eyelids, lips and neck.
Warts are common in children over the age of 3 years. The peak incidence is around 12 to 16 years of age. Warts are uncommon after the age of 25 years. An Australian study on school children showed 22% of 4-6 year olds, and 24% of 16-18 year olds to have warts. This distribution is apparently equal in males and females.
Warts are spread by skin to skin contact, and acquired through sites of minor trauma. Children are especially prone to warts because their immune systems are not mature.
Warts are more common in people with already damaged skin, for example with eczema.
Warts are diagnosed by simple observation of the appearance of the growth. Sometimes warts may be difficult to distinguish from moles, skin tags, calluses or even skin cancer. If the doctor suspects skin cancer they will recommend that the growth is removed and inspected under the microscope.
Most warts disappear on their own within 2 years of their appearance. It is therefore important that any treatment option does not cause any harm to the individual. For this reason reassurance and patience should be the mainstay of treatment Appropriate footwear reduces the risk of developing plantar warts in pressure areas of the foot.
Specific treatment measures include:
- Destruction of warts
- Immunostimulation to try and prompt an immune reaction to HPV
- Paints – These contain a substance, which causes the skin to peel off (and the wart with it). It should be applied to the wart with the sharp end of a toothpick to avoid irritation of the surrounding skin. Often it may be useful to cover the wart with an adhesive tape to enhance the penetration of the paint.
- Pastes – also cause the skin to peel off and are especially useful for plantar warts. There is a need to protect the surrounding skin with tape, then apply the paste to the wart and cover for 1-7 days. Once the chosen period is over, remove the plaster and peel away the skin. Reapply if necessary.